Ultrasensitive Near‐Infrared InAs Colloidal Quantum Dot‐ZnON Hybrid Phototransistor Based on a Gradated Band Structure

• DOI: 10.1002/advs.202207526
• Publication Date: 2023-04-24T03:00:31Z
• Authors: Jong‐Ho Kim; Byung Ku Jung; Su‐Kyung Kim; Kwang‐Ro Yun; Junhyuk Ahn; Seongkeun Oh; Min‐Gyu Jeon; Tae‐Ju Lee; Seongchan Kim; Nuri Oh; Soong Ju Oh; Tae‐Yeon Seong
• Keywords: Photodiode

Amorphous metal oxide semiconductor phototransistors (MOTPs) integrated with colloidal quantum dots (QDs) (QD-MOTPs) are promising infrared photodetectors owing to their high photoconductive gain, low off-current level, and compatibility pixel circuits. However, date, the poor mobility of conventional MOTPs, such as indium gallium zinc (IGZO), toxicity lead (Pb)-based QDs, sulfide selenide, has limited commercial applications QD-MOTPs. Herein, an ultrasensitive QD-MOTP fabricated by integrating a high-mobility oxynitride (ZnON)-based MOTP lead-free arsenide (InAs) QDs is demonstrated. A new gradated bandgap structure introduced in InAs QD layer that absorbs light, which prevents carriers from moving backward effectively reduces electron-hole recombination. Chemical, optical, structural analyses confirm movement photoexcited graded band structure. The novel exhibits outstanding performance responsivity 1.15 × 105 W-1 detectivity 5.32 1016 Jones at light power density 2 µW cm-2 under illumination 905 nm.